Process of magnetically concentrating ore



l(No Model.)

2 sheets-sheet 1. G. CONKLING.

PROCESS 0F MAGNBTIGALLY CONGBNTRATING ORB.

` Patented Nov. 18, 1890.

V/flll /NVENTOH (furdan [nflzny By Mw, .52am/n@ V4/% h ATTORNEYS (No Model.) 2 Sheets-Sheet 2.

G. CONKLI'NG. PRoeBss 0F MAGNBTIGALLY QONGENTRATING ORB. No. 441,060. Patented Nov. 18, 1800.

J'Iyl y@ JM@ v4! ula ATTORNEYS cess being pointed out in Nirnn STATES Ferron.-

anni* GURDON 'coNKLING7 or GLENS FALLS, New' YORK.

vPuooiass oF MAGNETICALLY coNcENTRA-r'luo ORE.

SPECIFICATION forming part of Letters Patent No. 441,060, dated November 18, 1890.

Application filed October 12,1889. Serial No. 326,773. No model.)

To @ZZ whom it may concern:

Beit known that 1, GURDoN CoNKLINe, a citizen of the United States, residing at Glens Falls, in the county of W'arren and State of New York, have invented new and useful Improvements in the Process forGoncentrating Iron Ore, of which the following is'a specification.

This invention relates to a new process for concentrating ore containing iron,

the following specification and claim.

The accompanying -drawings represent in Figure l a longitudinal vertical section of' a magnetic separator, which may be used in carrying out a certain part of my process; and

Fig. 2 is a plan or top view of another mag- Retie-separator; which may-be used in carrying out another part of my. invention.

Similar letters indicate corresponding parts.

If a man comes in possession of amine his first question is, can I work this mine with a profit? If he finds that -he can he works the mine; but if he finds that he will lose rather than profit he will let the mine lie idle.

The object of myinvention is to reduce the cost of concentratingiron ore to such an extent that iron mineswhich heretofore could not he worked without loss can be worked with a profit.

It is a well-known fact that iron ores d'ier Very much in their granular formation and in their richness of iron. The granular formation of some ores is such thatcubes of, say, a quarter of au inch and under, contain com- 'paratively pure ore, while with other oresthe granular formation is such that the cubes formed of pure ore are equal to the twentieth or even the thirtieth part of an inch. It is also a well-known fact that the cost of crushing ore depends upon the ineness to which the ore is to be crushed; and, furthermore, the longer the crushing `operation is continued the larger becomes the quantity of powdered or iiowered ore produced bythe crushing operation, and that this powdered ore entails a great loss in the percentage of pure ore 0btained by the process of concentration. For instance, the cost of crushing iron ore -to half an inch is, say, ten cents per ton, the cost of crushing the same kind of ore to a quarterof an inch is twenty cents per ton, and the cost said proof crushing the same to one-eighth o f an inch isforty-five cents per ton, and at the same time in carrying en the crushing operation to an eighth of an inch a large quantity of powdered ore isproduced, which is extremely difticult to save, and the consequence is a loss in money and in ore.

In carrying out my process with an iron ore, the granular formation of which is such that cubes of, say, a quarter ot'- an inch and under are formed of pure ore, I proceed as follows: I first crush the ore to a .quarter-inch, (such Ii'neness being necessary, because in being crushed the lumps of ore do not split up in exact lines of the granular formation above to the action of strong magnets, so that not only those fragments which consist of pure iron; ore will be attracted, but also all the fragments which are composed of a large percentage of gangue and a small percentage ofl iron ore, and consequently thev gang'ue which passes away as tailings in the process of concentrating contains very little iron ore.

In carrying out this part O f my process an` apparatus may he used such as illustrated in Fig. 1 of the drawings, in which the letter A designates the endless belt, which .extends over rollers B B and is placed vin an inclined position. F is amagnet, which is situated .in

the interior of 'the belt A close to its upper' branch. E is a trough over which the crushed ore mixed with water is fed to the belt A, and

S is a spray-pipe for washing the particles of'y ore which are attracted bythe magnet. The belt moves in the direction of arrow l, andl the particles which are attracted by the magn'et'are carried by the belt A over the pulley B, and they are collected in the receiver L.

The particles which are not attracted by the magnet run down over the pulley B and are collected in the receiver K. IThe mass which has been attracted by the magnets and collected in the receiver L' is composed of {parti-V cles from a quarterof an inch down, and many f of the larger particles contained inthis mass are composed of iron ore andl ganguc still attached and not having been mechanically separated in the crushing process,- and in order to eliminate this gangue from the mass I submit the same to asecond crushing voperation, and the recrushed mass is then exposed IOO g an inchin a'comparatively short time; but in order to reduce the inass which is to be reerush ed still farther I selectscrecns the rn eshcs,

- of which permit cubes of, say, aneighth of an inch or under to pass through, while they refuse the lumps of larger size, and I pass the entire mass'.from the receiver L .to lthese screens. 4The coarser particles refused by the screens' are then recrushed to, say, one-eighth of an inch and again submitted to the action 'of magnets.V

From this explanation it is apparent that the bulk ofthe mass which has to be recr'ushed ls'much smaller than the bulk of the mass which must be treated in the first crushing operation, and' if it shouldbe attemptedto crush'the entire mass in the first crushing opl eration to' aneighth of an inch .the cost ofthe crushing process would be more than-doubled,

and at the same time a large quantity of 4powdered ore would be produced, and the conse-4 quence -would be a loss inmoney and in iron ore, which in inany cases would be fatal to the working of a mine from an economical point of view. l

The operation of recrushing the particles refused by the screens canbe effected in a comparativelyshort time, and very little, if any, powdered ore is reduced, since themass which is to be recrue ed consists of particles of a quarter-inch and under, each particle containing a greater or less amount of iron ore, and the bulk of this entire mass is small-say one-eighth of the bulk of themass which must be treated in the 'first crushing operation.

For the purpose of exposing the rec'rushedv mass to the action of' magnets, I can use .with

.advantage an` apparatus such as shown in Fig,

2 of the drawings. This apparatus consists of a main .belt A and the secondary belt C, which extends at right angles over the main belt A, and n'the'intcrior of which, close to its lower branch, are situated the magnet-SF F. The mass to be separated is fed to the main belt A-through the hopper E, and the magnetic particles which are attracted by the magnets F are carried away by the belt C in thev direction of arrow 1, while the ganguel which remains on the belt A is carried away in the direction ofarrow 2.

From the foregoing example it will be readily understood thatbefore the concentrating process is applied to a given .quantity -ot iron orcl it. is first necessary to tind out the largest natural granular formation ofthe ore in or` .der to be able to'determine the ineness to which the ore'. is to be crushed inthe irstand afterward in the second crushing operation. What I claim as new, and desire to secure byfLetters Patent, is

' The process of concentrating iron ore, which consists in first coarsely crushing the ore to a size required by its natural granular formation wit-hout reducing ,any'considcrable proportion of the ore to dust, then concentrating the ore by the action of magnets, then screening 'this concentrate to separate the richer ore, then recrnshing the 'ore-refused' by the screen,and finally concentrating the recrushed V ore by the action of the magnets, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of' two subscribing witnesses. v

GURDON CONKLING.

Witnesses:

J. VAN SAN'rvooRD, E. F. KASTENHUBER. 

